Collins COBUILD Advanced Learner’s Dictionary

under|study /ʌ ndə ^r stʌdi/ (understudies ) N‑COUNT An actor's or actress's understudy is the person who has learned their part in a play and can act the part if the actor or actress is ill. □ [+ to ] He was an understudy to Charlie Chaplin on a tour of the U.S.A…

under|take /ʌ ndə ^r te I k/ (undertakes , undertaking , undertook , undertaken )

1 VERB When you undertake a task or job, you start doing it and accept responsibility for it. □ [V n] She undertook the arduous task of monitoring the elections.

2 VERB If you undertake to do something, you promise that you will do it. □ [V to-inf] He undertook to edit the text himself.

under|tak|er /ʌ ndə ^r te I kə ^r / (undertakers ) N‑COUNT An undertaker is a person whose job is to deal with the bodies of people who have died and to arrange funerals.

under|tak|ing /ʌ ndə ^r te I k I ŋ/ (undertakings )

1 N‑COUNT An undertaking is a task or job, especially a large or difficult one. □  Organizing the show has been a massive undertaking.

2 N‑COUNT [oft N to-inf] If you give an undertaking to do something, you formally promise to do it. □  When he delivered his budget he gave an undertaking to increase spending on health.

under|tone /ʌ ndə ^r toʊn/ (undertones )

1 N‑COUNT [in N ] If you say something in an undertone , you say it very quietly. □  'What d'you think?' she asked in an undertone. □  Well-dressed clients were talking in polite undertones as they ate.

2 N‑COUNT If something has undertones of a particular kind, it suggests ideas or attitudes of this kind without expressing them directly. □  …a witty, racy story with surprisingly serious undertones.

under|took /ʌ ndə ^r tʊ k/ Undertook is the past tense of undertake .

under|tow /ʌ ndə ^r toʊ/ (undertows )

1 N‑COUNT If there is an undertow of a feeling, that feeling exists in such a weak form that you are hardly aware of it, but it influences the way you think or behave. □ [+ of ] …an undertow of sadness.

2 N‑COUNT An undertow is a strong current of water that is moving below the surface current and in a different direction to it.

under|used /ʌ ndə ^r juː zd/ also under-used ADJ Something useful that is underused is not used as much for people's benefit as it could be. □  At present many schools' sports grounds are grossly underused. □  …areas where muscles are underused and underdeveloped. □  …underused land.

under|uti|lized /ʌ ndə ^r juː t I la I zd/ in BRIT, also use underutilised ADJ [usu ADJ n] Underutilized is a more formal word for underused . □  They had to sell off 10 percent of all underutilized farmland.

under|value /ʌ ndə ^r væ ljuː/ (undervalues , undervaluing , undervalued ) VERB If you undervalue something or someone, you fail to recognize how valuable or important they are. □ [V n] We must never undervalue freedom. ●  under|val|ued ADJ □  Even the best teacher can feel undervalued.

under|wa|ter /ʌ ndə ^r wɔː tə ^r /

1 ADV [ADV after v, n ADV ] Something that exists or happens underwater exists or happens below the surface of the sea, a river, or a lake. □  …giant submarines able to travel at high speeds underwater. □  Some stretches of beach are completely underwater at high tide. ● ADJ [ADJ n] Underwater is also an adjective. □  …underwater exploration. □  …a retired underwater photographer.

2 ADJ [ADJ n] Underwater devices are specially made so that they can work in water. □  …underwater camera equipment. □  …a pool of clear water lit by underwater lights.